CDP and LLDP are both discovery protocols used to find information about first hop neighbor network devices. The Cisco Discovery Protocol (CDP) is a proprietary Data Link Layer protocol developed by Cisco Systems. It is used to share information about other directly connected Cisco equipment, such as the operating system version and IP address. CDP …
Category Archive: Networking
Aug 21
DHCP Snooping on Cisco Catalyst Switch
DHCP snooping acts like a firewall between untrusted hosts and trusted DHCP servers. DHCP snooping performs the following activities: • Validates DHCP messages received from untrusted sources and filters out invalid messages. • Builds and maintains the DHCP snooping binding database, which contains information about untrusted hosts with leased IP addresses. • Uses the DHCP …
Aug 21
How to deny access for servers in the same VLAN on Cisco switch
In this scenario we have two servers connected on the same VLAN so typically they will be able to communicate directly and do not pass default gateway where you could perform ACL filtering. To disallow network devices from direct communication use command “switchport protected” under interface configuration. Configuration Example: enable configure terminal ! interface FastEthernet0/1 …
Jul 27
Entering a ? (Question mark) into Cisco IOS command
To get the question mark “?” into Cisco IOS configuration from command line simply type “Ctrl + V”, and the enter the “?” character. Example of use for this would be user password including “?” sign.